U.S. Pat. Nos. 4,798,594 and 4,895,565, among others such as Stevens U.S. Pat. Nos. 4,000,739 and 4,421,296, disclose catheter hemostasis valves which are mounted in a housing on the end of a catheter, typically a catheter sheath introducer. Such a catheter is used to facilitate the introduction of other catheters and guidewires into the vascular system of a patient, while minimizing injury to the patient at the access site. This is particularly used in situations where one or more catheters are inserted into and removed from the patient repeatedly, for example as in angioplasty. The presence of the catheter sheath introducer causes the trauma to the body to be limited to only one catheter entering at the body access site. All other catheters and guidewires pass through the catheter introducer, and thus are not traumatic to the body at the access site.
Catheter sheath introducers are known to carry a hemostasis valve which comprises a slit elastomeric partition or membrane carried in a housing. While the prior art shows many different designs of such membrane type hemostasis valves, there is still a desire for improvement in the performance of such valves with respect to their ability to seal against leakage of blood, as catheters and guidewires of varying diameters are passed through the valve. Also, it is important for the friction encountered as one advances a catheter or a guidewire through a catheter sheath introducer to be as low as possible. By this invention, improvements in both the sealing characteristics of the membrane valve of this invention and the frictional characteristics of the valve are achieved, to provide a partition valve for a catheter which exhibits improved characteristics over the prior art.
Furthermore, difficulties in resealing and friction are particularly encountered among the larger diameter catheters, for example catheters of a french six size and greater. By this invention a hemostasis valve is provided which is particularly capable of providing improvements in reducing friction and in the resealing of the valve, when used in conjunction with such larger diameter catheters.